(1) Field of the Invention
This invention relates to a method and an apparatus for placing concrete under water. More particularly, the invention relates to an improved tremie tube having a novel valve device.
(2) Description of the Prior Art
With the progress of the recent construction engineering, the need to place concrete or other hydraulic materials under water have been much increased.
When foundations or pedestals are constructed under water with concrete, a certain quantity of fresh concrete is placed step by step since the area to deposit the concrete is large, which is different from the construction of postholes. If the concrete is placed through the so-called tremie tube step by step, the water runs into the tube each time the tremie tube is lifted from the deposited concrete. Therefore, it has been regarded as unsuitable to use the conventional tremie tube for such a case. However, if the influx of water from the outlet of the tremie tube when the supply of concrete is ceased, can be avoided, the utility of the tremie tube will be much improved.